The present invention relates to shock absorbers or dampers, such as shock absorbers used on automotive vehicles, and more particularly, to an infinitely adjustable shock absorber that utilizes variable fluid pressures to change the dampening characteristics of the shock absorber, both during its compression stroke and its recoil stroke.
In the past, it has been recognized that the ability to change the dampening characteristics of hydraulic shock absorbers or dampers would be an advantageous and desirable improvement. Numerous attempts to do this have been undertaken, but there remains a heretofore unsatisfied need for a shock absorber whose dampening characteristics may be readily and easily changed over a relatively wide range and which can still be manufactured at a reasonable, competitive cost.
In some proposed adjustable hydraulic shock absorbers, damping force levels were not very consistent and repeatable because of the variation in the spring constant of the mechanical springs employed to bias the valves. Similarly, recoil to compression force ratios were limited to the ratio of the piston rod diameter to piston assembly diameter. Others required a relatively large number of component parts to achieve changes in dampening forces. The usage of such numerous parts increased the cost and complexity of the proposed shock absorbers. These are negatives to the successful commercial exploitation of the shock absorbers.